Відео

This is awesome question. Best rate of climb is where the plane has the most surplus power. In props and jets that's going to be faster than Vld. Best angle is where the plane has the most surplus thrust. In props that's slower. In jets best angle of climb is nearly the same as best glide. Minimum sink is where the least power is required, slower than best glide. Best angle of glide is where the plane has the most lift compared to drag. At best glide speed. Rates are dependent on surplus or deficits in power. Angles are dependent on surplus or deficits in thrust. Power looks at forces over distance and time, so think force and speed. Thrust just looks at straight pounds of thrust and pounds of drag.

@@jonathanzarinnia884 Thanks! Great discussion. This is the level of detail that's great to find in aviation YT. I think I understand what's going on. There are two slightly different perspectives how the power curve applies to real engines and props, which are dependent on airspeed. 1. The traditional approach (which I believe is exemplified by the Navy book you referenced) is to build the power curve based on lift and drag performance. This involves determining the sum of the effects of induced and parasitic drag components, which can be summarized in a "power required" curve, which is the amount of power that the aircraft would have to provide at various airspeeds in order to remain level. This curve will necessarily be convex and have a minimum point, which corresponds to the best ratio of lift to drag, and we call the associated airspeed V_ld(max). However, this is only a true minimum point in the case that the same power can be provided at all airspeeds. This is true at idle, so this works for determining V_minsink, since the engine and prop are not contributing anyway. But at any non-zero thrust level, the fact that power is a function of airspeed means that the min point as per V_ld(max) won't correspond to an optimal airspeed for climb. 2. The other approach, which I'm calling the Denker approach (since it's what's used in See How It Flies), is to flip the "power required" curve into a "power available" curve, which looks similar but it's upside-down. But more importantly, Denker factors the performance of the engine and the prop into the power available curve, so at non-idle power, the curve represents the surplus or deficit at power across a range of airspeeds in that configuration which includes the position of the throttle (and prop pitch, etc.), and not solely aerodynamic effects. This curve does factor in the engine, and so it's maximum point would differ from V_ld(max). This is what Denker is calling Vy. The question is what are the characteristics of this portion of the power curve, between Vy at a given thrust, and V_ld(max)? (I recognize that this region is likely to be only a couple of knots in the kinds of airplanes that we fly, but it's still an interesting discussion point.) If I'm at V_y, and i begin to pitch up, I'm not able to hold altitude as well, so it feels to me like the back-side of the power curve. Whether that effect is due to loss of aerodynamic efficiency or due to the ineffectiveness of the powerplant, I'm not sure it matters as a pilot. Does anything interesting happen when you cross V_ld(max) one way or the other?

Thanks! Glad you enjoyed it!

Thanks! That really keeps me motivated!

Love the Citabrias!

Clip wings are really nice.

Yes I can. I've been working an a video analyzing loss of control but I'm struggling to do it justice. A slip video would be a great project!

That's a great question! It's one I've been waiting for. Pardon the long reply, because I have a bunch of points teed up. It's not Utility Class. It's also not Normal, Restricted, Aerobatic or any other class. The Piper J-3C is certified under CAR 4 before those classes were a thing. The TCDS if I recall is A691. If someone has a PA-12 or PA-18 then these would be a no-no. That said there are maneuvers I won't do in the J-3. Negative G and snap-maneuvers, for example. Negative G are tough on the motor. Snaps are hard on the empennage. I also increase the maintenance interval on attach hardware, etc. The Cub makes primary aerobatics accessible on a tight budget, and I think that does a lot to improve our collective airmanship when access even to Citabrias let alone Pitts may be prohibitively costly. That said people CAN get the wrong ideas from these videos and start looping their 172s and Cherokees. I'm NOT about to support that nonsense. On the balance of things I think we, collectively, suffer more from atrophy in our airmanship than we do from pushing too hard. That said we can't talk about exploring an airplane's envelope without discussing practical and legal limitations around us. Great question! Keep 'em coming!

Thanks! 👍

Thank you! It's an excuse to doodle on my phone.

We have the same year Cubs! Also with metal spars. If you haven't taken a basic aerobatics course, get a few hours in with an instructor. Once that's done I hope you have a good time looping your Cub! It's pretty gentle and a hoot to boot.

Glad you enjoyed the video. More to come. When it comes to definitions I'm using American IAC definitions, and the half Cuban Eight is one of the maneuvers. To your point hower, there are things on this maneuver which would not cut it in a competion environment. We aren't holding a 45 downline while we roll back to level. Our loops aren't round. Etc. These are some of the compromises to keep oil pressure up among other things. Always good to talk with someone who's direct. Keep it coming.

@jonathanzarinnia884 Thanks ! No worries... (This grew to be longer than expected..., maybe get a coffee and prepare to enjoy the journey ?). I was a sort of autodidactic (Dunning Kreuger Effect driven ?) Aeroplane Freak who got into very early Ultralights - in fact they were still called "Minimum Aircraft" as a teenager..., in 1978. Later I worked for Sportair Aviation at Bankstown, Sydney, me being the Aircraft Detailer on 2nd-hand machines, and Assembler on new units, coming to us in Shipping Containers, or being ferried over the Pacific & needing the Ferry-Tanks removed, Seats put back in, and all the Oz Airworthiness Corrective Modifications made to meet our Safety Standards (things like fireproofing the Fuel Lines Firewall-forward...). As well as undercutting the Authorised Dealerships by direct importing Cessnas from the Factory and not having to provide Warranty (!), my Boss legitimately had the Oz Agency for Bellanca and Pitts... So, back in the day I met a retired Wing Commander RAAF who dropped in with his Pitts S-2a, and then a year later we met again when I was a Student Nurse hanging out at the Tamworth Aero Club on a Saturday morning - they'd called him in to run 30 minute "Aerobatic Trial Instruction" flights ; so I produced my Helmet & Goggles from my car's glovebox and in 2 days I racked up 2 hours & 4 landings. As a diligent little Biggles Freak, I'd read what I could, and I was doing OK with Loops & Snap Rolls, but when asked to try a "Cuban-8" I didn't know what that was.... In Oz I'd never heard of the manoeuvre, growing up - sort of the Olde Colonial Blackwater effect, and the happenings at International Aerobatics Competitions post WW-2 simply never penetrated this far down the pipeline. After the explanation I sort of came up to speed on it, but I enjoyed Stall Turns more - sufficient time to admire the view while going up/down in a straight line, perhaps... A year after that I spent a fortnight of my first-year holidays camping in a Caravan at the Narromine Soaring Centre, soloing on day 4 of their 5 day Ab-Initio course in a Blanik L-13, then having a second week converting onto and being let loose, soaring in an IS-28. My final solo in a Sailplane was 2 Hrs: 13 min., bringing my total time to 15 hrs: 10. Ten years later, groundbound all the time, after buying an unfinished, partly botched Scratch built Plans-up project..., redesigned & rebuilt big chunks of it, and designed & carved my idea of a Propeller for it ; it took me for it's Maiden First Fright in a New Prototype... A lot of people had misgivings - and ultimately they were n't entirely wrong ; in that after staying strictly in Test Pilot mode for the first 5 hours ; then I went flying in-company with a more experienced pilot whose machine (the first Prototype Bailey-Moyes Dragonfly - designed for Aerotowing Rogallo Hang Gliders) climbed literally 5 times better than my machine, a video of which can be found in my "Personal Aeroplanology"... Playlist, titled, "The 22-Hp, VJ-24w...; World's 1st Ultralight Motor-Glider...!". The Aeroplane did not want to go there, and it took me three attempts to land in the 200 yard Paddock selected, following Old Mate down and in ; landing in the Village of Red Range to have Coffee in my home with the Wife & Kids, in full Bigglesworth mode..., Ultralights out on an Excursion, kinda thing. Then, stupidly, I allowed myself to be talked into a downwind takeoff - when the actually correct answer was to have taken the Wings off, lifted it over the Fence and trailered it back to the Airstrip. So, we broke each other...; hitting the Fence and going over it Inverted, before landing in the Potato-Patch. The Jensen is still unrepaired, in it's Trailer, 25 yards away ; because I haven't been sufficiently rich, or bored, to get myself motivated to rebuild my second Aeroplane - the first one may be viewed on the Tubes (or if you're really keen, you can make the pilgrimage to visit it in person...), by searching YT or my Aeroplanology Playlist for it. Most recently, about 2 & 1/2 years ago I posted, " National Transportation Museum ; Visiting My First Aeroplane...!" And there's a truly Potato-Cam. standard 13 year-old effort titled, ponderously..., "The 8-Hp, 1975, Red Baron Skycraft Scout ; World's 1st Legal Minimum Aircraft"... I was it's third owner, and when it took me for my First Solo flights, up and down the Runway at Olde Bowral Airfield, it was making it's last Flights - and I didn't ever break it, so therefore it survived to be chained up. Revered for it's absolute Purist Minimalism. The Wright Brothers had a better Aeroplane in 1903. They had a 4-cylinder, 12.5 Hp 4-stroke Engine, reduction-driving two big Contra-Rotating Propellers to eliminate P-Factor..., they had Double-Surface Aerofoils - with Ribs & Spars inside their Wings..., and they had 3-Axis Controls - featuring Wing-Warping.... The 3rd Pre-production Mk-1 Scout has a single-cylinder 8 Hp motor, with one Chain reduction-driven Propeller for lots of P-Factor..., it has Single-Surface Aerofoils - Dacron in Tension with a Bolt-Rope hemmed to anchor the Leading-Edge in the Sail-Track of the extruded Boat-Masts which served as Leading-Edge Spars, and Cambered Aluminium "Slats" sewn unto Chordwise Pockets on the Wings..., and it has lots of Dihedral with a High-Wing layout, and all-flying Stabilators with a Finless Rudder - both actuated by the Joystick. The Throttle and Ignition Switch completed the Cockpit furniture, the Fuel Shutoff-Tap was under the Fueltank, operable only when standing beside the stationary machine. They didn't begin putting Wing-Warping on Skycraft Scouts until the advent of the Mk-3 in 1982...; with either the 18 hp Fuji-Robin or a 35-hp Rotax-377. When a friend of mine spun in, in his 35-hp Mk-3 Scout, in 1995..., I bought the Engine from his Estate ; and I originally thought to put that onto a rebuilt Jensen..., but I'm a bit of an Activist Greenie, too, y' see. Somehow I couldn't work up much enthusiasm to rebuild my Ankle-breaking Levitation-Machine, merely to be able to climb up into the Sky to fart CO-2 while making slow-moving Lawnmower-Noises, so as to look down on all my neighbours...., kinda thing. Being fair, I do live atop a Ridge in the Forest, and my Doorstep is vertically superior to every Rooftop within 15 km in all directions ; so I can already look down on my neighbours' places, while slowly collecting the materials with which to restore the Jensen if so inclined. And, guess who's now logged 2,493 Km on a Road-Registered Electric Motorcycle, which I recharge via my Off-Grid Stand-alone Solar System. A spare 6,000 Watt Motor, with a Speed-Controller & Gearbox is only $1,500, and a spare 2.3 Kw/Hr Battery would be another $2,500...; and the ESC has 4 levels of Regenerative Braking. I visualise an 8-ft diameter Propeller at 1,125 RPM, to engage 4 times the Disc-Area, with vastly better "engagement" with the Air-Column - and the same Tip-speed as a 42" Toothpick cutting a loud little Hole in the Sky at 4,200 RPM, and making 132 lbs of "Residual Thrust" (lol) with it's Cooling-Fan. An Electric Ultralight Motor-Glider, running on Solar Power, able to go up to 11,000 ft, and then come back down at 500 ft/min and 50 mph, at Level 4 Regenerative Braking, and operating as a 450-pound Free-Flying Electric Wind-Turbine - recharging the Battery for a possible Go-around after any Missed Approach.... Now, THAT is deeply tempting to me - I could be the Solar-Electric equivalent of the Mad-Max Gyro-Kapitan, silently wafting around, looking down on the Collapsing of Civilisation...(!). However, sadly, the Beaurocrats repealed Air Navigation Order 95.10 about a decade ago, while I was looking the other way. If I rebuild the Jensen to fly on Renewable Power, then I have to go the full Outlaw-mode ; but my Pop-Rivetry is Aluminium, and RADAR exists, and I reckon the RAAF's F-35s will come hunting me if I try to fly - any time before they run out of Kerosene for their Fire-farting Sky-Chariots. And, by that stage, the motorbike will be more use to me than an Electric Ultralight Motor-Glider. But, it's a very nice style of a Daydream. To share the view, look in my Videos about a fortnight ago for a Chest-Camera facilitated Rideabout-Talkabout, titled, "Electric Motorcycling, Into The Trumpocalypse...; Accelerationism Now In Control...?". Food for thought, perhaps ; especially for you - over there in the middle of the approaching Muddle, so to speak. Another option..., 8 of my 23 Playlists are Wildlife Encounters, sorted by Species ; so one can spend many hours entranced by the wild unfenced Kangaros & Wallabies & Possums & Birds who all consider me to be their Family's pet Tame Human. I've been paying Council Rates on the hundred acre Endangered Species Sanctuary, within which I live, for 34 years at this point ; so I even understand and "speak" a little bit of Marsupial Body-Language and Gesture, and Vocalisation... Someone has to do it. Such is life, Live a good one... Stay safe. ;-p Ciao !

Glad you enjoy. I'm as prone to getting it wrong as anybody else, so I enjoy feedback/commentary.

More to come!

Wow! Thanks for sharing a little about your dad's life!

Pasting from WINGS OF SILVER PIPER J-3 Cub OPERATIONS MANUAL & POH - AvSport odd, don't assume accuracy: In general, as long as you have sufficient altitude and airspeed, you can, within limits, toss a Cub around pretty much as you please, due to its inherently low speed gentle habits. The J-3 is rated for an absolute maximum load of +6.15 Gs, and operational maximum load of +4.1 Gs. However, the J-3 not rated for very much negative G load, no more than - 2 Gs; so go easy with any maneuver that might incur negative G forces. Unless you are really wild, you will not get into much not much trouble in any event that, with skill, you can't pull yourself out of it without bending the bird or yourself.

@@nopenheimerthanks for the reply. The cub is such a gentle soul. I imagine it would be hard to get it to come apart. I'm probably a little over cautious but that's how you make old pilots - lol.

It's good you're thinking about this, and, yes it's the empennage that's the weak spot. Over 20000 airframes and 80+ years of flying, there is not much history of in-flight failures of the j-3. Citabrias and Decathlons are planes I love, but the Cub is harder to break than they are. Increasing maintenance by periodically replacing attach hardware is a good way to stay ahead of potential issues. It's also a cheap way to keep some peace of mind.

@ that sounds reasonable to me. I haven't been up in a legitimate piper j3 in probably 30 or 40 years. I love the plane and it's the best color in the world to be able to see. It's some of the flyingiist flying you can do I believe.

Great to hear!

Thanks! I'm working on my next video about roll upsets.

You have innate understanding of total energy management. It is always better on long runways.

Of course you can, but the pilot in this scenario was practicing a short-field takeoff, so it would completely defeat the purpose

@@thematt6705 Unless he was practicing the energy inefficient ACS short field technique, there was absolute no need to pitch to Vx pitch attitude as soon as Vx airspeed was reached. In actual short field takeoff situations, I have always found acceleration level in low ground effect to the obstruction to work. Tail up as soon as it can be elevatored up. Mains off much slower than Vso because the airplane will fly in low ground effect much slower than Vso, and out of ground effect airspeed. Push the stick forward to bracket/remain in low ground effect until the obstruction forces pitch up. Zoom over the obstruction with the outcome never in doubt. At Vx, the outcome is always in doubt.

Your question is an excellent one! The answer is "It depends", and it gets pretty technical. Strictly from a performance perspective the general performance of jets is a little different from props, and there's s a discussion to be had there. But there are other considerations to factor as well. The combination of technical and human factors here could make for an awesome video! This is also something I could demonstrate with either of the planes. I can write at length about this and still not cover all of the factors.

@@jonathanzarinnia884 Technically airspeed is altitude and altitude is airspeed and therefore they are of equal value. But ground effect is so powerful for acceleration, should it not be in a different bucket and be valued for the zoom reserve airspeed it provides, along with fuel energy. In the small trainers of 65-150 hp I flew in the Rockies, ground effect energy was surely 50% of my total energy on many high DA takeoffs. And we haven't even considered down drainage egress, but that is the potential energy of altitude. Like the ground effect, down drainage egress from the airport is free energy. Just don't try to go up fast enough to kill yourself. So perhaps together 75% of the energy available in an old and tired DC-65 Taylorcraft at Alamosa, Colorado when it was too hot for Continental Airlines to land/takeoff was ground effect and down drainage egress. The problem with more powerful airplanes is that we don't need this extra free energy...until we do. The problem with the Howard takeoff is that every bit of the hundred feet or so of altitude was bought with precious airspeed kinetic energy. None of that altitude was free and it was insufficient for recovery from inadvertent mush or stall. Wolfgang would ask us, "What does the airplane want to do." Does it want to maintain altitude or maintain trimmed airspeed? He got the nose down quickly but stall recovery is best done with knowledge that we are going to do it and with sufficient altitude to recover. If there had never been a PTS or ACS or V speed or Vx or Vy as appropriate, how many airplanes would still be here and how many pilots? We had more incidents and accidents just using the principles in "Stick and Rudder." We had no more fatalities, however. It seems we are quite well avoiding many of the old problems except inadvertent stalls around the airport and loss of control on landing with enough speed to kill airplanes and pilots. And then there are the go around LOC accidents. I got a D in college algebra and only took astronomy for non-science majors. I need some help with the math on what I know to be true from 17,000 hours at 200' or below crop dusting and patrolling pipelines.

Happy to help! As an instructor and airline pilot I'm thrilled to see a student pilot doing research. There are lots of wise people with different points of view on just about everything, most with good reason. Good luck with your flight training!